Switching and routing protocol for a fiber optic transmission system

Abstract

A system for transporting a plurality of analog and/or digital signals over an optical fiber can include one or more master modems for modulating digital signals and/or RF inserters modulating video signals. The RF signals from the modem(s)/RF inserters are up-converted resulting in frequency bands that are non-overlapping and are spaced apart within a single sub-octave. The sub-octave signal is then converted into an optical signal and directed onto an end of an optical fiber. At the downstream end of the optical fiber, the received optical signal is converted to an RF signal at an optical receiver. The RF signal is then filtered, down-converted and directed to a selected coaxial distribution unit. From the coaxial distribution unit, the RF signal is demodulated, e.g. at a slave modem, to recover the initial analog and/or digital signal.

What is claimed is: 
     
       1. A system for transporting a plurality of digital data signals, the system comprising:
 at least one RF inserter receiving a video signal and outputting an RF signal; 
 at least one master modem outputting a signal modulated with at least one digital signal; 
 an up-convertor system operating on RF signals downstream of an RF inserter and a master modem to output an RF signal having a frequency bandwidth within a single sub-octave; 
 an optical transmitter converting a single sub-octave RF signal downstream of the up-convertor system into an optical signal and directing the optical signal into an optical fiber; 
 an optical receiver downstream of the optical fiber converting the optical signal to an RF signal; 
 a down-convertor system receiving an RF signal downstream of the optical receiver and outputting an RF signal having the video signal encoded thereon; and 
 a slave modem receiving an RF signal having at least one digital signal encoded thereon downstream of the down-convertor system and outputting at least one digital signal, the slave modem configured to delay transmission of an upstream signal to the optical receiver until a transmit notification has been received from a master modem. 
 
     
     
       2. A system as recited in  claim 1  wherein a master modem receives a plurality of input digital signals and outputs a frequency-division-multiplexed (FDM) signal encoding at least two input digital signals. 
     
     
       3. A system as recited in  claim 1  wherein a master modem receives a plurality of input digital signals and outputs a time-division-multiplexed (TDM) signal encoding at least two input digital signals. 
     
     
       4. A system as recited in  claim 1  wherein a master modem establishes a TDM protocol configured to accommodate the present traffic volume demands on the slave modem. 
     
     
       5. A system as recited in  claim 1  wherein a master modem receives a plurality of input digital signals and outputs a frequency-division-multiplexed (FDM) signal encoding at least two input digital signals that is also time-division-multiplexed (TDM). 
     
     
       6. A system as recited in  claim 1  further comprising a coaxial distribution unit receiving an RF signal having at least one digital signal encoded thereon downstream of the down-convertor system and wherein the slave modem receives an RF signal having at least one digital signal encoded thereon downstream of the coaxial distribution unit. 
     
     
       7. A system as recited in  claim 1  further comprising a coaxial distribution unit receiving an RF signal having at least one digital signal encoded thereon downstream of the down-convertor system and wherein a master modem receives a plurality of input digital signals and outputs a time-division-multiplexed (TDM) signal establishing a TDM protocol configured to accommodate the present traffic volume demands on the co-axial distribution unit. 
     
     
       8. A system as recited in  claim 1  wherein the up-converter system comprises a plurality of up-convertors and an RF combiner, each up-convertor outputting a respective frequency band; the frequency bands being non-overlapping with each other and spaced apart from each other within a single sub-octave, and wherein the RF combiner produces a combined RF signal from the frequency bands. 
     
     
       9. A system as recited in  claim 1  wherein the down-converter system comprises a plurality of down-convertors and an RF splitter producing signal fractions from the transmitted RF signal; and wherein each down-convertor receives a signal fraction downstream from the splitter and outputs an RF signal having the video signal encoded thereon. 
     
     
       10. A system as recited in  claim 1  wherein the RF inserter modulates the video signal on a carrier signal using quadrature amplitude modulation (QAM). 
     
     
       11. A system as recited in  claim 1  wherein the video signal is selected from the group of video signals including an analog video signal and a digital video signal. 
     
     
       12. A system as recited in  claim 1  wherein a monitoring signal is received by the RF inserter with the video signal. 
     
     
       13. A system as recited in  claim 1  wherein a telemetry signal is received by the RF inserter with the video signal. 
     
     
       14. A device for transmitting a plurality of digital data signals into an optical fiber, the device comprising:
 at least one master modem receiving a plurality of digital signal inputs and outputting a multiplexed RF signal encoding at least two input digital signals, wherein a master modem is configured to communicate a transmit signal to a downstream slave modem to initiate a transmission of an upstream signal by the slave modem; 
 an up-convertor system operating on at least one RF signal downstream of a master modem to output an RF signal having a frequency bandwidth within a single sub-octave; and 
 an optical transmitter converting a single sub-octave RF signal downstream of the up-convertor system into an optical signal for input into an optical fiber. 
 
     
     
       15. A device as recited in  14  wherein the multiplexed signal encoding at least two input digital signals is selected from the group of signals comprising a frequency-division-multiplexed (FDM) signal, a time-division-multiplexed (TDM) signal and a signal that is frequency-division-multiplexed (FDM) and time-division-multiplexed (TDM). 
     
     
       16. A device as recited in  claim 14  wherein the up-converter system comprises a plurality of up-convertors and an RF combiner, each up-convertor outputting a respective frequency band; the frequency bands being non-overlapping with each other and spaced apart from each other within a single sub-octave, and wherein the RF combiner produces a combined RF signal from the frequency bands. 
     
     
       17. A device as recited in  claim 14  further comprising at least one RF inserter receiving a video signal and outputting an RF signal and wherein the up-convertor system operates on at least one RF signal downstream of an RF inserter to output an RF signal having a frequency bandwidth within a single sub-octave. 
     
     
       18. A method for transporting a plurality of digital data signals, the method comprising the steps of:
 outputting an RF signal modulated with at least one digital signal from at least one master modem; 
 up-converting at least one RF signal downstream of a master modem to output an RF signal having a frequency bandwidth within a single sub-octave; 
 converting a single sub-octave RF signal into an optical signal and directing the optical signal into an optical fiber; 
 converting an optical signal to an RF signal downstream of the optical fiber; 
 down-converting an RE signal and outputting an RF signal having at least one digital signal encoded thereon; 
 receiving an RF signal having at least one digital signal encoded thereon at a slave modem; 
 outputting at least one digital signal from the slave modem; 
 delaying transmission of an upstream signal by the slave modem; and 
 transmitting the upstream signal upon receipt of a transmit notification from a master modem. 
 
     
     
       19. A method as recited in  claim 18  wherein a master modem receives a plurality of input digital signals and outputs a frequency-division-multiplexed (FDM) signal encoding at least two input digital signals. 
     
     
       20. A method as recited in  claim 18  wherein a master modem receives a plurality of input digital signals and outputs a time-division-multiplexed (TDM) signal encoding at least two input digital signals. 
     
     
       21. A method as recited in  claim 18  further comprising the step of receiving an RF signal having at least one digital signal encoded thereon at a coaxial distribution unit and wherein the slave modem receives an RF signal having at least one digital signal encoded thereon downstream of the coaxial distribution unit.